Might start out at the gym soon, need motivation

I (14m) had literally nothing to do all day so I thought I should start at the gym, I have done research about everything, I picked a gym that's both affordable and near to my house, but the only thing holding me back are my parents, I am literally excited to workout but at the same time scared to ask my parents that if they'll allow to me to join it, for all my life, they have given me a low self esteem, embarrassed me Infront of my friends and other family members. I'm not the typical athletic guy that's why my father hates me, I have a feeling that they'll make fun of me and rub it off, but I should try atleast. Thank you for listening to my rant :)